export default{
  namespaced:true,
  state:() => ({
    // 购物车的数组，用来存储购物车中每个商品的信息对象
    // 每个商品的信息对象，都包含如下 6 个属性：
    // { goods_id, goods_name, goods_price, goods_count, goods_small_logo, goods_state }
    cart: JSON.parse(uni.getStorageSync('cart') || '[]')
  }),
  mutations:{
    addToCart(state, goods){
      const findResult = state.cart.find(x => x.goods_id === goods.goods_id)
      
      if(!findResult){
        state.cart.push(goods)
      }else{
        findResult.goods_count++
      }
      this.commit('m_cart/saveToStorage')
    },
    saveToStorage(state){
      uni.setStorageSync('cart', JSON.stringify(state.cart))
    },
    //更新购物车中商品的勾选状态
    updateGoodsState(state, goods){
      const findResult = state.cart.find(x => x.goods_id === goods.goods_id)
      
      if(findResult){
        findResult.goods_state = goods.goods_state
      }
      this.commit('m_cart/saveToStorage')
    },
    //更新购物车中商品的数量
    updateGoodsCount(state, goods){
      const findResult = state.cart.find(x => x.goods_id === goods.goods_id)
      
      if(findResult){
        findResult.goods_count = goods.goods_count
      }
      this.commit('m_cart/saveToStorage')
    },
    //根据id从购物车中删除对应商品的信息
    removeGoodsById(state, goods_id){
      state.cart = state.cart.filter(x => x.goods_id !== goods_id)
      this.commit('m_cart/saveToStorage')
    },
    //更新购物车中所有商品的勾选状态
    updateAllGoodsState(state, newState) {
      state.cart.forEach(x => x.goods_state = newState)
      this.commit('m_cart/saveToStorage')
    }
    
    
    
  },
  getters:{
    //购物车中所有商品的总数量
    total(state){
      // let c = 0
      // state.cart.forEach(x => c += x.goods_count)
      // return c
      return state.cart.reduce((total, item) => total += item.goods_count, 0)
    },
    //购物车中已勾选商品的总数量
    checkedCount(state){
      return state.cart.filter(x => x.goods_state).reduce((total, item) => total += item.goods_count, 0)
    },
    //已勾选商品的总价格
    checkedGoodsAmount(state){
      return state.cart.filter(x => x.goods_state).reduce((total, item) => total += item.goods_count * item.goods_price, 0).toFixed(2)
    }
    
  }
}